Latest on my W202 C230K aka ''Rough Rough''

[John Jones Jr]

I got a bit time today to carry out the MAF relocation. M111's that have had their boost pressure increased tend to suffer from one or two flat spots. In my case it was mainly somewhere around 3000-3500 rpm. It was frustrating too and I hate flat spots.

The MAF normally resides right on top of the I.C. outlet pipe, but to cure the flat spot (thanks to the smarter people out there than me!) the secret is to move it as close as reasonably possible to the Throttle Body and hey presto flat spot vanishes. Plus, my engine is now running a little richer. Previously the max AFR was 12.2:1 @ WOT, now it's down to low 11's which I'm quite happy about. The engine mightn't be making more power but it's a safer AFR, also the LTFT's are gone from '0' to -9%, indicating that she is running richer.

A couple photo's. First one is the new MAF location, almost parallel with w/screen w/bottle and the other photo showing a hose in place of the MAF at the I.C. outlet.

 

[John Jones Jr]

I reset the ECU and decided a fast/spirited run was in order. The poor guy behind in his new VAG diesel didn't know which way I went as I blasted ahead overtaking several cars at a time in one hit. Then I managed to blow off one of the boost pipes at just a touch over 10 PSI in third! Happy days. :bannana:

 

[John Jones Jr]

I got a bit time today to carry out the MAF relocation. M111's that have had their boost pressure increased tend to suffer from one or two flat spots. In my case it was mainly somewhere around 3000-3500 rpm. It was frustrating too and I hate flat spots.

The MAF normally resides right on top of the I.C. outlet pipe, but to cure the flat spot (thanks to the smarter people out there than me!) the secret is to move it as close as reasonably possible to the Throttle Body and hey presto flat spot vanishes. Plus, my engine is now running a little richer. Previously the max AFR was 12.2:1 @ WOT, now it's down to low 11's which I'm quite happy about. The engine mightn't be making more power but it's a safer AFR, also the LTFT's are gone from '0' to -9%, indicating that she is running richer.

A couple photo's. First one is the new MAF location, almost parallel with w/screen w/bottle and the other photo showing a hose in place of the MAF at the I.C. outlet.

A little update and reminder for myself as it's too easy to forget the actual figures and parameters etc when changing things about.

While the ECU was nearing the end the it's relearn process the AFR's when down to 10.9 @ WOT and the LTFT settled @ -12.5%, basically the engine is running rich, a bit too rich by all accounts. Now, to my limited knowledge there's no way to adjust the fuel mixture other than I relocate the MAF back to it's original position at I.C. outlet and injure the flat spot I mentioned above.

Thankfully, I still had a 4.0 BAR FPR fitted, the original spec is 3.5 BAR. I refitted the 3.5 and did a quick 30 mile blast. LTFT decreased to -9.4% with AFR @ WOT rising to 12.3. So, she's running leaner now and from what I understand these engines with increased boost pressure produce max power with an AFR of 12.2, so I'm on the money power wise and hope I'm also safe with fuelling. If so, things are possibly looking very good and I'm currently happy with the power and throttle response.

I'll now carry out another ECU relearn and go from there.

 

[John Jones Jr]

O.k. the latest engine operation parameters after a spirited 370 mile round trip mainly on A roads.

Max Boost pressure (just before rev limiter) 10-10.5 Psi.
LTFT -10.5%.
AFR 11.2-11.4 @ WOT.
Timing -18 @ WOT.
Ambient Temp 25c/IAT 35c.

MPG 32.75

 

[John Jones Jr]

The last update for this year, possibly till late Spring next year.

I took the old girl off the road last month as I wasn't using it much and with winter on it's way that wouldn't help the bodywork even if it's still in reasonably in good condition, no sill rust or boot floor rust - no structural rust at all in fact but it has a bit on the front wings and lower corner of the doors (what's new on a W202).

Over the winter if I do get to work on her, I'll concentrate on fitting the Water/Methanol Injection kit which it transpires I need to two more parts for which are classed as accessories (hands up I didn't research all options on reservoir locations properly) and consider overhauling the rear subframe and arms as the bushes are past their sell by date. Other than that, I might even give it a proper clean. And I better fix the intermittent non operation of the heater fan, it's been getting worse and annoys the hell out of me as it will work when I don't need it!.